Low Impact Development and Remodeling Information

Before urban development in the Central Coast, as much as 50% of rainwater was infiltrated into the soil, replenishing groundwater supplies, contributing to stream flows and sustaining vegetation; another 40% was released into the atmosphere through evapotranspiration. Only about 10% of rainwater contributed to storm water runoff (rainwater that flows over the land surface). With urban development, the amount of impervious areas like roofs and pavement have drastically increased the amount and rate of storm water runoff. The use of Low Impact Development (LID) strategies can help to protect and enhance the environmental quality of our rivers, creeks and watersheds by slowing and infiltrating stormwater back into the ground, mimicking pre-development hydrology.

State and federal storm water regulations require development and remodeling projects in the City to incorporate design standards and Best Management Practices (BMPs) in order to reduce storm water pollution and minimize the potential for erosion.

STORM WATER MANAGEMENT REQUIREMENTS FOR
DEVELOPMENT AND REMODELING PROJECTS
IN THE CITY OF SANTA CRUZ

The Central Coast Regional Water Quality Control Board adopted Resolution R3-2013-0032 in July 2013 approving new Post-Construction Stormwater Management Requirements for Development Projects in the Central Coast. The municipalities of the Central Coast started enforcing these new requirements on March 6, 2014. To learn more about the Central Coast requirements, click here.

For projects that require the installation of structural storm water management BMPs property owners will need to submit a signedStorm Water BMP Maintenance Agreement before obtaining a Building Permit. Once a project with structural storm water BMPs is completed, the property owner will be required to submit a maintenance log to the City annually.

Central Coast Region Stormwater Control Measures Sizing CalculatorThis calculator was developed to help projects subject to Tier 3 of the requirements size bioretention facilities to meet the runoff retention performance standards. Information that must be input into the calculator is listed in the BMP guidance and in the sizing calculator instructions provided below. Project applicants can either use this calculator or the "simple method" provided in the BMP guidance to design facilities to meet the runoff retention requirement.

This calculator was developed by Santa Barbara County under a State Proposition 84 grant.

Watershed Management Zones
For projects subject to Tier 3 of the new requirements, the Regional Board incorporated a spatial element to the requirements in the form of Watershed Management Zones. Links to City of Santa Cruz-specific Watershed Management Zone maps for Runoff Retention in PDF format are below:

85th and 95th Percentile Rainfall Depths
The Central Coast Post-Construction Requirements stipulate that municipalities must require Regulated Projects to use rainfall statistics provided by the Central Coast Water Board or to calculate site-specific rainfall depths determined from local rainfall data using USEPA’s methodology. See below for City of Santa Cruz Rainfall Depth Maps based on Central Coast Water Board data:

Urban Sustainability AreasIn order to support mixed-use redevelopment and infill within City limits, the City designated areas identified in our General Plan 2030 as community and regional business centers and primary transportation corridors as "Urban Sustainability Areas." Within Urban Sustainability Areas, redevelopment project that are subject to Tier 3 Requirements and that meet certain density requirements may claim reduced runoff retention requirements. See the City's Urban Sustainability Area Designation for more detail.

Additional Source Control BMPs for Projects with Special Site Conditions

Proposed projects with special site conditions shall incorporate relevant source control measures in their operation and maintenance plans. See the links below for relevant City of Santa Cruz and CASQA BMP guidance. Projects with special site conditions include:

Learn more about rain gardens and swales and how they work with this video:

For practical and eco-friendly ways to protect your property and the environment from the effects of storm water runoff, please click on the link below for the brochure "Slow it. Spread it. Sink it! A Homeowner's Guide to Greening Stormwater Runoff" which was published by the Resource Conservation District of Santa Cruz County.

If you would like a copy of this brochure, please call Suzanne Healy, Environmental Projects Analyst, at 831-420-5131, or Angie Gruys, Resource Conservation District, at 831-464-2950 x22.

For more information about the City's Storm Water BMP Requirements for development and redevelopment projects, please contact Agnes Topp, Environmental Projects Analyst, at 831-420-5423.